Ablation catheters, i.e. catheters with a device for tissue ablation by necrotizing the tissue, are variously used, for example to treat arteriosclerosis, to treat vessel malformations, tumors, etc. Special importance is also attached here to the treatment of ventricular tachycardia or heart flutter. A heart attack often leaves scars, in particular in the ventricle, which negatively affect the stimulus conduction capability in the myocardium of the ventricle. Stimulus conduction capability is essential for the functioning of the heart, it being known that said functioning is based on very complex electro-physiological phenomena based on stimulus currents which are generated and routed via the ions of the heart muscle cells and via which contraction of the heart muscle is controlled. In the ventricle, in the region of the scars resulting from a heart attack, there is locally damaged cell tissue, the degree of damage diminishing toward the edge of the damaged tissue. Particularly in this region containing only partially functionally impaired cells there is a risk that stimulation current conduction is insufficient, resulting in a continuous pulse being emitted which can lead to an atrial flutter.
This “re-entry phenomenon” is mostly countered by selectively making scars in the region of the heart muscle by catheter ablation, in order to kill off completely the only partially damaged tissue in the region of the scars resulting from the heart attack, since dead tissue has no effect on stimulus current conduction. The scars produced by ablation are frequently positioned as a function of an electrophysiological determination of the site of the ablation.
Although catheter ablation generally takes place with X-ray monitoring, i.e. the doctor can identify the position of the ablation catheter in the heart from the X-ray image, he nevertheless has no information on the actual condition of the tissue in the treatment area and whether he is actually performing ablation at the place where it is required.
DE 102 12 841 A1 describes a catheter with an ablation facility, it being possible to detect the tip of the catheter using a position-recording device.
U.S. Pat. No. 5,056,503 discloses a very specifically designed endoscopy device which has a solid state capture element, i.e. an imaging element.